ICAR Technical Series no. 7 - Nitra Proc.

Lipinski et al.Milk hygiene quality was estimated after collecting milk samples of 250-300ml at the purchase point, which were then delivered, to the DairyCooperative laboratory in containers cooled by ice. The following qualityparameters were determined:• Total number of micro organisms;• Coliform count;• Whiteside test;• Milk acidity;• Milk density.The performed investigations showed that:• none of the examined farms fulfilled standards of milk raw materialrequired for milk extra class;• 12 % of milk producers delivered milk whose quality allowed itsclassification to class I;• 24% of milk producers delivered milk classified as class II;• 64% of milk producers delivered milk classified as class III.The most frequent source of contamination of raw milk with bacteria waspoorly washed and disinfected equipment for machine milking.Approximately 90% of bacteria in raw milk derived from milkingequipment and only 10% from other sources such as mastitis or airbornebacteria. In unwashed or poorly washed equipment used formachine-milking, bacteria adjust to such environment and multiply veryrapidly between milkings and later quickly contaminate freshly obtainedmilk.Therefore, effective washing and disinfection of milking machines isessential if farmers want to maintain the number of bacteria in milk at alow level. In addition, it helps to reduce the danger of transferringmicroorganisms, which cause udder diseases. The performedinvestigations showed that the majority of milk suppliers washed anddisinfected their milking machines properly and only in 14 dairy farmsparts of milking machines were found to have been washed poorly.The performed investigations also evaluated milking techniques, i.e. suchactivities as:• udder training;• pre-milking;• hand stripping;• machine stripping with udder training.It is well known that udder training causes irritation of nerve ends sensitiveto touch. They receive outside stimuli and transmit them to the centralnervous system from which signals are sent to the udder stimulating milksecretion. When teat cups are mounted onto non-stimulated teats, thenICAR Technical Series - No 7239